Dry-cleaning composition



Patented Aug. 17, 1943 DRY-CLEANING COMPOSITION Lawrence H. Flett, Hamburg, N. Y., assignor to Allied Chemical & Dye Corporation, a

tion of New York Serial No. 250,916

No Drawing. Application January 14, 1939,

11 Claims. (01. 252-161) This invention relates to improvements in the dry cleaning of fibrous, textile and'related materials. It relates particularly to improved compositions for use in dry cleaning and to processes of dry cleaning in which said improved compositions are employed.

It is well known that certain types of textile fabrics and materials such as leather cannot be cleaned by means of ordinary soap an water since they are prone to shrink, harden, rinkle and/r fadewhen they are wtted with water. For the cleaning of such materials a dry cleaning process must be used. In such dry cleaning processes, volatile organic solvents such as naphtha:

trichlorethylene, carbon tetrachloride, gasoline,

tached to' a carbon atom of the carboxylic acid residue representedby -.li; and the total number of carbon atoms in A and B is at least 12.

Compounds of the above-described general class have been found to give excellent results in improving dry cleaning compositions, particularly if the said compositions also contain small amounts of water. However, it has been found that certain of these compounds give even better benzene, Stoddards solvent, etc, are used. These solvents are eifective for removing from the to) rice or materials practically all grease stains as well as dust and dirt which commonly adhere to the greasy spots. It is further known that if a small amount of water is sufliciently well dispersed in the dry cleamng fluid that water-sol uble stains such as those caused by sugary liqui candy, soft drinks, etc., are removed without adversely ailecting the material so treated.

According to the present invention, a, dry cleaning composition is used which contains a essential components a dry cleaning solvent, or mixture of dry cleaning solvents, and at least one salt of a. sulfonated aliphatic monocarboxylic ester of a monohydric alcohol, said ester containing at least 13 carbon atoms of which at least 3 are in the alcohol residue. As employed herein, the term "sulfonated aliphatic monocarboxylic ester of a monohydric alcohol denotes generically alkyl group oflower carbon content. I

results than the class as a whole. Thus, the salts of sulfonated esters of the above general formula which are characterized by the presence of analkyl group of 8 or more carbon atoms (in the radical represented. by A or B abovel-are preferred. Those compounds which contain an alkyl found to be more efl'ective than those withan This invention contemplates the use fonated esters of the above general class in the of the sulgroup having 12 to 18 carbon atoms have been form of salts in which the acidic hydrogen of the sulfate and/or sulfonate group is replaced by an inorganic or organic salt-forming radical.

Among the more easily obtained. salts 'are the sulfonate (sulfonic acid) and sulfate derivatives of aliphatic monocarboxylic esters in which a sulfonic acid radical is attached through its sulfur atom to a carbon atom of the carboxylicacid residue of the ester (a "sulfo-aliphatic monocarboxylic ester") or in which a sulfate radical is attached through an oxygen atom thereof to a S-ACOOB in which A is theresidue of an aliphatic monoammonium, alkali metal. and alkaline earth metal salts. Salts in which the acidic groups are neutralized by organic bases (such as mono-, di-.-or

tri-ethanolamine, pyridine, ethyleneamine, amylfonated ester of the above general formulaor in part with such a compound and in part with other acidic materials, whichadvantageously may have detergent properties. Examples of such other acidic materials are: di-isopropyl naphthalene sulfonic acid, n-propyl acid sulfate; hy-

drochloric acid, naphthalene sulfonic acid, sulfuric acid, phosphoric-acid, etc.

The presence as dry cleaning assistants of the hereindeflned sulfonated esters in a dry cleaning fluid has been found to be particularly efleccarboxylic acid; B is the residue of a monohydric alcohol and contains 3 or more carbon -atoms;' 8 represents either SO:H or -O:H and is attive in enabling the dry cleaning fluid. in which water is normally practically immiscible to hold 1 in finely dispersed form a limited amount of water.---' It has been found that by using said sulfonated esters a substantially greater amount of water in relation to the-amount of dry cleaning assistant present can be held in a'well dispersed f rm in v the dry cleaning solutionthan was h'e etofore possible. With the dry cleaning assistants of this I invention the material to be cleaned may be solvent-washed in the absence of water with excellent results. However. better results are usually obtained by adding a small amount of water as such to the dry cleaning bath. Due to the presence of the sulfonated esters the water becomes incorporated and dispersed in such an extremely finely divided state for the dry cleaning composition that water-sensitive materials can be dry cleaned in such water-containing compositions without danger of water spotting. The exact amount of water needed in any given case varies somewhat according to the type of soil which is to be removed,and this generally varies with the particular material to be treated. For example, about 0.25% of water has been found to give good results in many cases. In general there must not be so much water present that it is in poorly dispersed form and so causes water-spotting of the material being dry cleaned. As is well known, the amount of moisture which the material will tolerate without suffering water-damage (wrinkling,

shrinking, etc.) depends upon the particular mab terial and its state of dryness as well as upon the degree of dispersion of the moisture in the dry cleaning solvents. The amount of water which a dry cleaning solvent can hold in a very finelydispcrsed Or non-wetting state with respect to the materials to be cleaned depends altogether upon the dry cleaning assistant which is added to the solution, and it has been found that the members of the class of dry cleaning assistants hereinbefore defined are very substantially better for the purpose than those used according to the prior art. Practical comparative tests show that the dry cleaning compositions of this invention are a substantial improvement over compositions heretofore used.

Substantial economies in dry cleaning are shown by the use of the hereinbefore defined sulfonated esters in the dry cleaning compositions of this invention. This is due to the fact that much less of the said ester is necessary to pro.- duce an excellent cleaning efiect than has previously been used of the currently-known dry cleaning assistants. Thus, it has been found that, when the sulfonated esters represented by the above general formula are used, less than one-third of the usual amount of dry cleaning assistant need be added to the dry cleaning solvent to prepare adequate dry cleaning compositions.

In addition, the use as dry cleaning assistants of the compounds represented by the foreoing general formula imparts an increased cleaning action to the compositions containing them, and obviates harmful and undesirable effects on the color and finish of the material cleaned therewith. Further, the aforesaid sulfonated compounds are for the most'part not lime-sensitive and therefore they do not form insoluble calcium salts nor cause undesirable deposits of insoluble calcium salts to be formed in the dry cleaning baths as do many compounds heretofore used, when water introduced in such baths contains water-soluble calcium salts.

The dry cleaning compositions of this application may be made from many dlfierent types of dry cleaning solvents. Heretofore each type of dry cleaning assistant was usable and compatible only with one or a limited class of dry 'clean- 7 ing solvents, whereas the dry cleaning assistants which are used for preparing the dry cleaning compositions of the present invention-may be used with excellent results in practically any dry cleaning solvent. The presence of said sulfonated esters as dry cleaning assistants in the dry cleaning compositions of this invention also js has the very desirable efi'ect of greatly decreas ing the internal electrical resistance of inflammable solvents or solvent mixtures; thereby substantially decreasing the danger of fire from spark discharges or static electricity.

In many modern dry cleaning plants it is the practice to remove undissolved dirt from the dry cleaning solution by filtration. The presence of thehereinbefore defined sulfonated esters in the dry cleaning baths aids in decreasing the clogging efiects of the dirt on the filter media and retards the development of back pressures in the filters. In this way the period during which the dry cleaning solution can'be recirculated before plugging thefilter is substantially increased with resulting economy in operation.

The invention is illustrated by the following examples in which the parts are by weight:

Example 1.-A cleaning bath was obtained by mixing 3.0 parts of butyl ricinoleate' sodium sulfonate with 1115 parts of V. M. P. naphtha (a hydrocarbon mixture having a specific gravity of 0.746 and a boiling range of 215-320 F. and of which per cent of the distillate distilled be-- tween 215 and 279 F.). A piece of flannel soiled with tallow and carbon black was agitated mechanically in this dry cleaning composition for about half an hour. The flannel was withdrawn and allowed to dry. The dry cleaned mate'rial was substantially free from soil and very bright, showing very good cleaning action by the composition.

Example 2.-A cleaning bath was obtained by shaking 2.0 parts of sodium lauryl sulfo acetate with 1115 parts of V. 'M. P. naphtha. A piece of. soiled flannel cleaned with this composition showed very good cleaning action.

Example 3.-'I'he same procedure was followed as in Example 2 but 2.5 parts of water were added to the solution. Even better cleaning than in Example 2 was obtained.

', amples 1, 2, and 3 contain rather large. amounts of materials such as inorganic sodium salts, e. g., solium chloride and sodium sulfate than probably have little, if any, cleaning action, but the amounts of sucli commercialpreparations used always contain at least about l.5 parts by weight of sulfonated ester in the form of the sodium salt. The sulfuric acid compounds which are required to be components ofthe dry cleaning compositions of my invention are thus seen to be unaffected by the presence of inert foreign substances and it is not necessary that the compounds be used in a very pure state.

Instead of the sulfonated esters employed in the above examples, other sulfonated esters of the class hereinbefore defined may be substituted as effective dry cleaning assistants in the dry sulfonated ester, salt to organic substantially water-immiscigladry cleaning solvent .or solvent mixture need not be greater than 1.0:100 and is preferably less than 0.32100. In fact, drycleaning compositions containing as little as l to 3 parts of the dry cleaning assistants of the present in- I vention per 1000 parts of solvent by weight have been found to give highly satisfactory cleaning.

are represented by the general formula above are effective as dry cleaning assistants in practically any volatile organic liquid of the dry, cleaning type, for example, naphtha, trichlorethylene, tetrachlorethylene, Stoddards solvent, benzene, gasoline, and carbon tetrachloride.

' bon atoms of which at least 3 are in-the alcohol Salts of the sulfonated esters which are employed in accordance with the present invention may be prepared in any convenient manner and by any one of several known methods. Forexample, a suitable ester may be acted upon by a sulfonating agent under conditions such as to avoid extensive break-down of the original ester linkage, or an aliphaticsulfonic or sulfuric monocarboxylic acid may be esterifled in the'carboxyl group. In some cases a sulfuric group may be introduced by reacting a bisulfite with a suitable ester containing a halogen atom attached to an aliphatic carbon atom; Other methods known or describedin the art may alsobeused.

The sulfonated compounds employed in accordance with this invention have been found to give excellent results in the. cleaning of all kinds of materials and fabrics such as wool, silk, cotton, leather, and rayon. The compositions are efiective in the removal of all types of' soil, dirt, or stains. They may be used in practically any machinery or device used in commercial dry cleaning and in any particular purifying or recovery process which is applied to the dry cleaning fluid.

The addition of various other products such selected from the group consisting of ammonium, alkali metal, alkaline earth metal and organic ammonium salts, the amount of said salt beingnotmore than 1 per cent of the weight of the volatile organic dry cleaning-solvent.

3. A dry cleaning composition comprising an emulsion of water in a volatile organic dry cleaning solvent, the water being inthe; internal phase, ,and a salt of a sulfato-aliphatic monocarboxylic ester of a monohydric alcohol, as a dry cleaning assistant andas an\ emulsifying agent for the water, said ester containing at least 13 carresidue, and said salt being selected from the group consisting of ammonium, alkali metal, alkaline earth metal and organic ammonium salts, the amount of said salt being notmore than 1 per cent of the weightof the volatile organic dry cleaning solvent.

4. A dry cleaning composition comprising an emulsionof water in a volatile organic dry cleaning solvent, the water being in the internal phase,

and a salt of a sulfo-aliphatic monocarboxylic ester of a monohydric alcohol, as a dry cleaning assistant and as an emulsifying agent for the water, said ester containing at least 13 carbon.

atomsof which at least 3 are in'the alcohol residue, and said .salt being selected fromthe group consisting of ammoniumialkali" metals.

alkaline. earth metal, and organic ammonium salts, the amount of said salt being not more than 1 per cent of the weight of the volatile organic' dry cleanin solvent. I

5. A dry cleaning composition'comprising an emulsion of water in a volatile organic dry cleaning solvent, the water being in the internal phase, and a salt of a sulfatoealiphatic monocarboxylic ester of a monohydric alcohol, as a dry cleaning assistant and as an' emulsifying agent for the water, said ester containing at least 13 carbon atoms of which at least 8 carbon atoms are in the alcohol residue, and said salt being selected as other organic sulfuric acid derivatives. soaps,

fatty acids, etc. do not substantially affect the excellent properties of the dry cleaning comemulsion of water in a volatile organic dry cleaning solvent, the water being in the internal phase,

and a salt of a suifonated aliphatic monocarboxylic ester of a monohydric alcohol, as a. dry cleaning assistant and as an emulsifying agent for the water, said ester containing at least 13 carbon atoms of whichat least 3 are in the alcohol residue, and said salt being selected from the group consisting of ammonium, alkali metal, alkaline earth metal and organic ammonium salts, the amount of said salt being not more than 1 per cent or the weight of the volatile organic dry cleaning solvent.

2. A dry cleaning composition comprising an emulsion of water in a volatile organic dry cleaning solvent, the water being in the internal phase, and a salt of a sulfonated aliphatic monocarboxylic ester of a monohzdric alcohol, as a dry cleaning assistant and as an emulsifying agent for the water, said ester containing at least 18 carbon atoms of which at least 8 carbon atoms from the'group consisting of ammonium, alkali metal, alkaline earth metal and organic ammonium salts, the amount of said salt being not more than 1 per cent by weight of the volatile organic dry cleaning solvent.

6. A dry cleaning composition comprising an emulsion of water in a volatile organic dry cleaning solvent, the water. being in the internal phase, and a salt of a sulfate-aliphatic monocarboxylic ester of a monohydricalcohol, said ester containing at least 13 carbon atoms and the alcohol residue ofsaid ester containing 12 to 18 carbon atoms, as a dry cleaning assistant and as an emulsifying agent for the water, and said salt being selected from the group consisting of ammonium, alkali metal, alkaline earth metal and organic ammonium salts, the amount' of said salt being not more than 0.3 per cent of' the weight of the volatile organic dry-cleaning solvent. v r

I'L'A dry cleaning composition comprising an emulsion of water in a volatile organic dry cleaning solvent, the water being in the internal phase,

and-a salt of a sulio-aliphatic monocarboxylicester of a monohydric alcohol, as'a dry cleaning assistant'and as an emulsifying agent. for the water, said ester containing at least 13 carbon atoms of which at least 8 are-in the alcohol residue, and said salt being selected from 'the group consisting of iammonium, alkali metal,

alkaline earth metal and organic ammonium I are in the alcohol residue, and said salt being Jo s t e ount of said salt bei g not more containing 12 to 18 carbon atoms,

than 1 per cent by weight of the volatile organic dry cleaning solvent.

8. A dry cleaning composition comprising an emulsion of Water in a volatile organic dry cleaning solvent, the water being in the internal phase, and a salt of a sulfo-aliphatic monocarboxylic ester of a monohydric alcohol, as a dry cleaning assistant and as an emulsifying agent for the water, said ester containing at least 13 carbon atoms and the alcohol residue 0 said ester d said salt being selected from the group consisting of ammom'um, alkali metal, alkaline earth metal and organic ammonium salts, the amount of said salt being not more than 0.3 per cent by weight of the volatile organic dry cleaning solvent.

9. A dry cleaning composition comprising an emulsion of water in a volatile organic dry cleaning solvent, the water being in the internal phase,

and an alkali metal salt of an alkyl ester oi sulfoacetic acid containing .12 to 18 carbon atoms in the alkyl group, as a dry cleaning assistant and as an emulsifying agent for the water, the amount of said salt being not more than 0.3 per cent by weight of the volatile organic dry cleaning solvent.

10. A dry cleaning composition comprising an emulsion of water in a volatile organic dry cleaning solvent, the water being in the internal phase, and sodium lauryl sulfoacetate in an amount not exceeding 1 per cent of the weight of the volatile organic dry cleaning solvent, as a d'ry'cleaning assistant and as an emulsifying agent for the water.

11. A dry cleaning composition comprising an emulsion of water in a volatile organic dry cleaning solvent, the water being in the internal phase. and butyl ricinoleate sodium sulfonate in an amount not exceeding 1 per cent of the weight of the volatile organic dry cleaning solvent, as a dry cleaning assistant and as an emulsifying agent for the water. 

